Ventilator-associated pneumonia (VAP) is one of the most common healthcare-associated infections in neonatal and pediatric intensive care units (ICU) in the U.S., resulting in significant morbidity and mortality. In order to monitor and preven VAP, the National Healthcare Safety Network (NHSN) for the Centers for Disease Control and Prevention (CDC) relies on surveillance definitions that are based predominantly on subjective criteria (e.g. clinical exam and CXR findings). When placed in a policy context, where HAIs such as VAP are increasingly targeted for public reporting and changes in reimbursement, the limitations of existing VAP definitions are self-evident. CDC is currently proposing changes to this quality measure for adult patients. However, much less is known about the potential impact of this measure in neonatal and pediatric populations. Our goals are to facilitate the development and evaluation of new quality measure for children called ventilator- associated complications (VAC). We focus our efforts on VAC because we believe it offers greater opportunities for prevention and improved quality of care and will also have greater acceptability among neonatal and pediatric ICU clinicians. We also seek to identify potential interventions to prevent the wide range of complications associated with ventilator use, in support of a VAC intervention bundle. The findings from this grant will inform national policy discussions regarding quality measures for outcomes associated with ventilator use in neonatal and pediatric populations. Thus, we propose the following specific aims: 1. to describe the incidence of ventilator-associated complications (VAC) and to evaluate the performance characteristics and prognostic accuracy of VAC to predict 30-day mortality among ventilated children in 4 U.S. hospitals. 2. To determine etiologies and risk factors for VAC in neonatal and pediatric ICU settings and 3. To identify potential key components of an intervention bundle targeting reductions in VAC